When did it all start.

I know the basic background and history of Scotch, but I would like to know a few details if anyone can help;-
1. When did whisky distillers start maturing the product before selling, ie was it all originally consumed as raw spirit. I am thinking that when it was illicitly produced the distillers would not have the inclination or the facilities to keep it lying around.
2. Whose bright idea was it to produce grain spirit rather than Malt.
3. When did we (the consumer) first start buying blended whisky.
4. When was whisky first sold by the bottle, what size / capacity were the bottles?
5. At what proof strength has whisky historically been sold.

Help on any of the above appreciated.